Wheel and brake drum assembly



Aug. 14, 1962 T. L. HIBBARD WHEEL AND BRAKE DRUM ASSEMBLY Filed Jan. 12,1959 INVENTOR.

rwamns A. fi/asnk United States Patent 3,049,379 WHEEL AND BRAKE DRUMASSEMBLY Thomas L. Hibbard, Birmingham, Mich., assignor to Kelsey-HayesCompany, Detroit, Mich, a corporation of Delaware Filed Jan. 12, 1959,Ser. No. 786,244 2 Claims. (Cl. 301-6) This invention relates to wheeland brake drum assemblies and refers more particularly to a wheel andbrake drum assembly of the type in which the wheel structure is mountedon the brake drum.

The invention has for one of its objects to provide a wheel and brakedrum assembly in which the wheel structure is mounted on the brake drumand the web of the drum is mounted on a rotatable member by fastenerswhich are concealed by the web when the assembly is viewed from theoutboard side.

The invention has for another object to provide a wheel and brake drumassembly in which the wheel structure is mounted on the brake drum andthe web of the drum is mounted on a rotatable member in a manner suchthat the web serves the additional function of a wheel center and isexposed on the outboard side to present a wheel body appearance.

Other objects and features of the invention will become apparent as thedescription proceeds, especially when taken in conjunction with theaccompanying drawing, illustrating a preferred embodiment of theinvention, where- FIG. 1 is a fragmentary radial section of a wheel andbrake drum assembly embodying the invention; and

FIG. 2 is a fragmentary elevation with the hub cap removed, looking inthe direction of the arrow II in FIG. 1.

Referring now more particularly to the drawing, 1 is the brake drum and2 is the wheel structure. The brake drum is a cast element in the formof a shell having the integral web 3 and annular flange 4 extendingalong the radially outer periphery of the web and projecting in anaxially inward direction or to the left as viewed in FIG. 1. The shellis cast of aluminum or magnesium, which are relatively light in weightand have high heat transfer characteristics. While aluminum or magnesiumare preferred, other materials may be employed. The annular flange 4 isformed with a series of circumferentially spaced heat dissipating ribs 5cast integrally with the flange. The web 3 has an outer annular radialportion 6 upon which the wheel structure is mounted, and an innerbolting-on portion 7 flaring from the radial portion radially inwardlyand axially outwardly. The web has a central circular opening 8, and anannular hub cap retaining formation 9 projecting axially outwardly fromthe web near its inner margin. The formation 9 defines a centralcircular opening 10 adapted to detachably receive a hub cap 11. The hubcap is fitted within the opening 10 and may have a threaded or snapengagement therewith or any other readily detachable form of connection.Equally spaced radially extending heat dissipating ribs 12 are castintegrally with the web on the outboard side thereof.

An annular cast-iron liner 13 is secured to the inner surface of flange4 for engagement by a suitable friction device, not shown. The brakedrum shell may be formed by casting in a sand or permanent mold or bydie casting, for example. Preferably the liner 13 is placed in the moldprior to casting and the brake drum shell is cast around the liner.During casting of the shell, a molecular bond is obtained between theliner and shell flange throughout the full 360 of contact. The procedureemployed for bonding the liner to the flange forms no part of thepresent invention and is fully described in an ap- 3,049,379 PatentedAug. 14, 1962 flange with a plurality of equally circumferentiallyspaced axially outwardly projecting wheel mounting bosses 14 whichterminate in radial faces. The bosses are formed with the axiallyextending sockets 15 open at the axially inner side of the web andhaving bolt holes 16 in the bottom Walls of the sockets. In the presentinstance, bosses are provided in each alternate space between adjacentribs 12.

The wheel structure 2 comprism an annular tire rim 17 and mounting tabs18. The rim 17 encircles the brake drum and is formed with a well 19.The tabs are spaced apart circumferentially with respect to the rimequal distances corresponding to the spacing between the wheel mountingbosses 1.4, and each tab has a generally axially extending portion 20welded to the bottom wall of the rim well 19. Each tab also has theradially inwardly extending portion 21 which is adapted to overlie aboss 14 and which has a central raised part 22 formed with a hole 23registering with a bolt hole 16. Fasteners are provided comprising bolts24 which extend through the registering holes 16 and 23 with the heads25 of the bolts seated against the bottoms of the sockets 15, and nuts26 are threaded on the outer ends of the bolts and bear against the tabsto draw them firmly against the radial surfaces of the bosses 14. Eachbolt 24 is serrated near the head to provide a gripping engagement withthe hole 16 frictionally resisting axial movement or rotation of thebolt relative to the drum and enabling tightening and loosening nut 26from the outboard side without otherwise holding the bolt. The boltsextend freely through tab holes 23 for mounting and demounting the wheelstructure. By means of the tabs 18, bolts 24 and nuts 26, the rim isdetachably secured to the brake drum so that the web of the drum servesthe additional function of a wheel center and the nuts are accessiblefrom the outboard side of the assembly for mounting and demounting thewheel structure.

A pluraiity of fasteners 27 are provided for detachably mounting thewheel and brake drum assembly on the flange 28 of the rear axle 29. Thebolting-on portion 7 of the web is formed on its inboard side with acircular series of spaced sockets 30 which are closed at the "bottom andhave permanently secured therein the cylindrical fastener elements ornuts 31 which are internally threaded. The axle flange is formed with acircular series of openings 32 spaced apart so as to register with thenuts 31. The fasteners 27 also include the cap screws 33 which areadapted to extend through the openings 32 and threadedly engage the nuts31 to detachably mount the web and hence the wheel and brake drumassembly on the axle flange.

During assembly, the brake drum is positioned on the axle with the nuts31 in register with the axle flange holes 32 and the cap screws 33 arethen fitted through the flange holes and threaded into engagement withthe nuts to draw the web of the drum tightly against the axle flange.Access to the cap screws 33 for this purpose may be had through theusual brake backing plate, not shown. Thereafter the bolts and nuts 24and 26 are employed to detachably mount the wheel structure on the drum.

The nuts 26 are accessible from the outboard side of the assembly sothat the wheel structure may be readily mounted and demounted. Thefasteners 27 composed of the nuts 31 and cap screws 33 are neithervisible nor accessible from the outboard side of the assembly and hencea person changing a wheel will not inadvertently remove the brake drum.The web of the drum is exposed on the outboard side and presents anattractive wheel body appearance. Moreover the heat dissipating ribs 12are exposed for maximum cooling.

The illustrated detachable connection between the brake drum web andaxle flange enables enhancing the outboard appearance of the web sinceit may be extended radially inwardly beyond the nuts and cap screws 31and 33 to provide the relatively long radial ribs 12 and requires only asmall hub cap. In other Words, a relatively large diameter hub cap isnot required for the purpose of covering the means for mounting theassembly on the axle flange.

As pointed out above, the drum shell is preferably formed of aluminum ormagnesium because of the high heat transfer characteristics of thesematerials. The web and ribs 12 are exposed on the outboard side formaximum cooling effect. Moreover, the exposed web gives the appearanceof a full aluminum wheel, where aluminum is uscd.

What I claim as my invention is:

1. In a wheel and brake drum assembly, a brake drum of high heatconductivity material having a generally radial web and an annularflange along the radially outer periphery of said web, a wheel structureincluding a rim encircling said brake drum and mounting tabs secured toand extending radially inwardly from said rim in overlying relation tothe outboard side of the radially outer portion of said web, threadedfastening elements accessible from the outboard side of the assemblyextending through registering apertures in said radially outer portionof said web and in the overlying tabs for detachably mounting said wheelstructure on said web, and fasteners for detachably clamping said web toa rotatable member, each fastener including cooperating engagingthreaded elements one of which is fixed to the inboard side of said webradially inwardly of said tabs, the material of said web covering andconcealing said fasteners when said assembly is viewed from the outboardside and rendering said fasteners substantially inaccessible from theoutboard side, said web having an integral extension projecting radiallyinwardly beyond said fasteners provided with means for detachablyholding a cover member, said web serving the additional function of awheel center, the outboard side of said web, including the integralextension thereof and except for the portions thereof overlain by saidtabs, being exposed for maximum cooling and to present a Wheel bodyappearance.

2. The structure defined in claim 1, wherein the said one element ofeach fastener is an internally threaded member and provided in a socketin said web, said sockets being open at the inboard side of said web andextending axially from their open ends terminating at the bottomsthereof short of. the outboard side of said web so as to be covered andconcealed by the material of said web between the outboard side of saidweb and the bottoms of said sockets.

References Cited in the file of this patent UNITED STATES PATENTS1,439,269 Siddeley Dec. 19, 1922 1,473,406 Harroun Nov. 6, 19231,602,560 Wahlberg Oct. 12, 1926 1,846,236 Wagenhorst Feb. 23, 19321,964,129 Miller June 26, 1934 2,095,054 Burger Oct. 5, 1937 2,205,323Tinnerman June 18, 1940 2,400,348 Greene May 14, 1946 2,402,743 FirthJune 25, 1946 2,409,516 Rosenthal Oct. 15, 1946 2,693,392 Grosch Nov. 2,1954 2,728,370 Neuscholz Dec. 27, 1955 FOREIGN PATENTS 498,058 GreatBritain M Jan. 3, 1939 857,160 Germany Nov. 27, 1952 1,056,131 FranceOct. 21, 1958

